android 图片操作

深碍√TFBOYSˉ_ 2022-05-18 05:48 145阅读 0赞

缩放

public static void resize(Bitmap bitmap, File outputFile, int maxWidth, int maxHeight) {
        try {
            int bitmapWidth = bitmap.getWidth();
            int bitmapHeight = bitmap.getHeight();
            // 图片大于最大高宽，按大的值缩放
            if (bitmapWidth > maxHeight || bitmapHeight > maxWidth) {
                float widthScale = maxWidth * 1.0f / bitmapWidth;
                float heightScale = maxHeight * 1.0f / bitmapHeight;
               //取小值
                float scale = Math.min(widthScale, heightScale);
                Matrix matrix = new Matrix();
                //图片变换处理 缩放
                matrix.postScale(scale, scale);
                bitmap = Bitmap.createBitmap(bitmap, 0, 0, bitmapWidth, bitmapHeight, matrix, false);
            }    
            FileOutputStream out = new FileOutputStream(outputFile);
            try {
                bitmap.compress(Bitmap.CompressFormat.JPEG, 80, out);
            } catch (Exception e) {
                e.printStackTrace();
            } finally {
                try {
                    out.close();
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

//保存图片

public static void saveBitmap(String outputPath, Bitmap bitmap) {
        // save image
        FileOutputStream out = null;
        try {
            out = new FileOutputStream(outputPath);
            bitmap.compress(Bitmap.CompressFormat.JPEG, 100, out);
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            try {
                if (out != null) {
                    out.close();
                }
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    }

//base64转bitmap

public static Bitmap base64tobitmap(String image) {
        if (TextUtils.isEmpty(image)) {
            return null;
        }
        byte[] bytes = Base64.decode(image.getBytes(), Base64.DEFAULT);
    
        Bitmap bitmap = BitmapFactory.decodeByteArray(bytes, 0, bytes.length);
    
        return bitmap;
    }

/**
     * 加载本地图片
     * 
     * @param url
     * @return
     */
    public static Bitmap getLoacalBitmap(String url) {
       try {
          FileInputStream fis = new FileInputStream(url);
          return BitmapFactory.decodeStream(fis); // /把流转化为Bitmap图片
       } catch (Exception e) {
          e.printStackTrace();
          return null;
       }
    }    
    //旋转拍照生成的图片的方向
    public static Bitmap getBitmapByUrl(byte[] data,int fangxiang) {
    
          Bitmap bitmap = null;
          try {
    
             bitmap = BitmapFactory.decodeByteArray(data, 0, data.length);
             // 根据拍摄的方向旋转图像（纵向拍摄时要需要将图像选择90度)
             Matrix matrix = new Matrix();
             matrix.setRotate(fangxiang);
             bitmap = FileUtils.comp(Bitmap
                    .createBitmap(bitmap, 0, 0, bitmap.getWidth(),
                          bitmap.getHeight(), matrix, true));
    
          } catch (Exception e) {
             e.printStackTrace();
             bitmap.recycle();
             bitmap = null;
             System.gc();
          } finally {
             if (fis != null) {
                try {
                   fis.close();
                } catch (IOException e) {
                   e.printStackTrace();
                }
                fis = null;
             }
          }
    
          return bitmap;
       }